U.S. patent application number 13/146264 was filed with the patent office on 2011-11-17 for base station apparatus, mobile station apparatus, and mobile communication system.
This patent application is currently assigned to SHARP KABUSHIKI KAISHA. Invention is credited to Toshizo Nogami, Hidekazu Tsuboi, Katsunari Uemura.
Application Number | 20110280189 13/146264 |
Document ID | / |
Family ID | 42395476 |
Filed Date | 2011-11-17 |
United States Patent
Application |
20110280189 |
Kind Code |
A1 |
Tsuboi; Hidekazu ; et
al. |
November 17, 2011 |
BASE STATION APPARATUS, MOBILE STATION APPARATUS, AND MOBILE
COMMUNICATION SYSTEM
Abstract
To keep PAPR low even when the same physical cell ID is used in
each component carrier, a base station apparatus 100 for combining
a plurality of component carriers to transmit has phase rotation
sections 105-1 to 105-n that provide phase rotation for each
component carrier, and a transmission section 108 that transmits
the component carriers provided with phase rotation to a mobile
station apparatus, where the phase rotation amount is determined
based on a physical cell ID common to component carriers.
Inventors: |
Tsuboi; Hidekazu; (Osaka,
JP) ; Uemura; Katsunari; (Osaka, JP) ; Nogami;
Toshizo; (Osaka, JP) |
Assignee: |
SHARP KABUSHIKI KAISHA
Osaka-shi, Osaka
JP
|
Family ID: |
42395476 |
Appl. No.: |
13/146264 |
Filed: |
January 6, 2010 |
PCT Filed: |
January 6, 2010 |
PCT NO: |
PCT/JP2010/050070 |
371 Date: |
August 5, 2011 |
Current U.S.
Class: |
370/328 |
Current CPC
Class: |
H04L 5/001 20130101;
H04L 27/2621 20130101 |
Class at
Publication: |
370/328 |
International
Class: |
H04W 4/00 20090101
H04W004/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 27, 2009 |
JP |
2009-015912 |
Claims
1. A base station apparatus that combines a plurality of component
carriers to transmit, comprising: a phase rotation section that
provides phase rotation for each component carrier; and a
transmission section that transmits the component carrier provided
with the phase rotation to a mobile station apparatus, wherein an
amount of the phase rotation is determined based on a physical cell
ID common to component carriers.
2. The base station apparatus according to claim 1, further
comprising: a physical cell ID/phase rotation amount correspondence
table that associates an amount of phase rotation which is
beforehand set based on a CM (Cubic Metric) value with the physical
cell ID, wherein the phase rotation section provides phase rotation
for each component carrier based on the physical cell ID/phase
rotation amount correspondence table.
3. The base station apparatus according to claim 1, wherein the
phase rotation section has a sign inverting section that inverts a
sign, and a replacing section that replaces a real part and an
imaginary part of an input signal with each other.
4. A base station apparatus that combines a plurality of component
carriers to transmit, comprising: a phase rotation section that
provides phase rotation for each component carrier; a CM
calculating section that calculates a CM value when a physical cell
ID is changed in any one of the component carriers; a control
section that sets the phase rotation section for an amount of phase
rotation based on the CM value; and a transmission section that
transmits the component carrier provided with the phase rotation to
a mobile station apparatus.
5. The base station apparatus according to claim 2, wherein the CM
value is a value when a transmission signal is a reference signal
of each component carrier, a primary synchronization channel, a
secondary synchronization channel, a broadcast information channel
or a combination thereof.
6. A base station apparatus that combines a plurality of component
carriers to transmit, comprising: a phase rotation section that
provides phase rotation for each component carrier; and a
transmission section that transmits the component carrier provided
with the phase rotation to a mobile station apparatus, wherein an
amount of the phase rotation is determined based on a physical cell
ID, while being changed based on the physical cell ID at certain
time intervals.
7. The base station apparatus according to claim 6, further
comprising: a physical cell ID/phase rotation amount correspondence
table that associates the physical cell ID with each amount of
phase rotation of the component carrier; and a physical cell
ID/phase rotation offset amount correspondence table that
associates the physical cell ID with a phase rotation offset amount
in the time domain to store, wherein the phase rotation section
provides phase rotation for each component carrier based on the
physical cell ID/phase rotation amount correspondence table and the
physical cell ID/phase rotation offset amount correspondence
table.
8. The base station apparatus according to claim 1, wherein the
base station apparatus changes a basis for the amount of the phase
rotation corresponding to the number of component carriers to
combine.
9. A mobile station apparatus that performs wireless communications
with the base station apparatus according to claim 1, wherein the
mobile station apparatus provides a signal received from the base
station apparatus with inverse phase rotation to phase rotation
provided in the base station apparatus.
10. The mobile station apparatus according to claim 9, wherein the
mobile station apparatus provides the inverse phase rotation based
on an amount of phase rotation that is beforehand notified from the
base station apparatus using an upper control signal.
11. The mobile station apparatus according to claim 9, further
comprising: a phase difference determining section that determines
an amount of phase rotation of each component carrier from a phase
difference between adjacent component carriers, wherein the mobile
station apparatus provides the inverse phase rotation based on the
amount of phase rotation determined in the phase difference
determining section.
12. A mobile station apparatus that performs wireless
communications with the base station apparatus according to claim
2, comprising: a physical cell ID/phase rotation amount
correspondence table that associates an amount of phase rotation
that is beforehand set based on a CM value with the physical cell
ID, wherein the mobile station apparatus acquires an amount of
phase rotation from the physical cell ID/phase rotation amount
correspondence table, and a physical cell ID of a base station
apparatus to connect, and provides a signal received from the base
station apparatus with inverse phase rotation to phase rotation
provided in the base station apparatus.
13. A mobile station apparatus that performs wireless
communications with the base station apparatus according to claim
8, wherein the mobile station apparatus provides a signal received
from the base station apparatus with inverse phase rotation to
phase rotation provided in the base station apparatus on a basis
for an amount of phase rotation corresponding to the number of
combined component carriers.
14. A mobile communication system comprising: the base station
apparatus according to claim 1; a mobile station apparatus
supporting EUTRA (Evolved Universal Terrestrial Radio Access); and
a mobile station apparatus supporting A-EUTRA (Advanced EUTRA).
15. The base station apparatus according to claim 4, wherein the CM
value is a value when a transmission signal is a reference signal
of each component carrier, a primary synchronization channel, a
secondary synchronization channel, a broadcast information channel
or a combination thereof.
16. A mobile communication system comprising: the base station
apparatus according to claim 4; a mobile station apparatus
supporting EUTRA (Evolved Universal Terrestrial Radio Access); and
a mobile station apparatus supporting A-EUTRA (Advanced EUTRA).
17. A mobile communication system comprising: the base station
apparatus according to claim 6; a mobile station apparatus
supporting EUTRA (Evolved Universal Terrestrial Radio Access); and
a mobile station apparatus supporting A-EUTRA (Advanced EUTRA).
Description
TECHNICAL FIELD
[0001] The present invention relates to a base station apparatus,
mobile station apparatus and mobile communication system for
performing wireless communications using a multicarrier
communication scheme.
BACKGROUND ART
[0002] Conventionally, Evolution (Evolved Universal Terrestrial
Radio Access; hereinafter, referred to as "EUTRA") of 3rd
Generation (hereinafter, referred to as "3G") radio access scheme
of cellular mobile communication, and Evolution (Evolved Universal
Terrestrial Radio Access Network; hereinafter, referred to as
"EUTRAN") of 3G network have been studied in 3GPP (3rd Generation
Partnership Project).
[0003] Further, 3GPP started studies on the 4th Generation
(hereinafter, referred to as "4G") radio access scheme (Advanced
EUTRA; hereafter, referred to as "A-EUTRA" or "LTE-A") of cellular
mobile communication, and 4G network (Advanced EUTRAN; hereinafter,
referred to as "A-EUTRAN"). In A-EUTRA, studies are made on support
for wider bands than in EUTRA and compatibility with EUTRA, and it
is proposed that a base station apparatus of A-EUTRA communicates
with a mobile station apparatus of EUTRA in each frequency band
(hereinafter, referred to as a "component carrier") obtained by
dividing a frequency band of A-EUTRA into a plurality of bands. In
other words, it is proposed that a plurality of component carriers
is provided with the function capable of transmitting a channel
with the same configuration as in EUTRA.
[0004] In EUTRA, it has been determined that an OFDMA (Orthogonal
Frequency Division Multiple Access) scheme which is tolerant of
multipath interference and suitable for high-speed transmission is
adopted as a downlink communication scheme. Further, in the
cellular mobile communication scheme, since a mobile station
apparatus receives signals transmitted from a base station
apparatus in a cell or sector that is a communication area of the
base station apparatus, it is necessary to acquire synchronization
with a slot and a frame in a radio frame of the base station
apparatus. The base station apparatus transmits a synchronization
channel SCH comprised of a defined configuration, and the mobile
station apparatus calculates correlation with a beforehand stored
synchronization channel SCH to detect the synchronization channel
SCH, and thus acquires synchronization with the base station
apparatus. In EUTRA, a primary synchronization channel P-SCH
(Primary SCH) and secondary synchronization channel S-SCH
(Secondary SCH) are assumed as a synchronization channel SCH.
[0005] FIG. 6 is a diagram showing an example of a configuration of
a radio frame in EUTRA. In FIG. 6, the horizontal axis represents
the time axis, while the vertical axis represents the frequency
axis. In a radio frame, 12 subcarriers (sc) on the frequency axis
and a slot that is a set of a plurality of OFDM symbols on the time
axis are configured as a unit, and a region split by 12 subcarriers
and one slot length is called a resource block (Non-patent Document
1). Two grouped slots are called a sub-frame, and further, ten
grouped sub-frames are called a frame. A plurality of resource
blocks is arranged consecutively in the frequency domain, and 100
resource blocks are arranged in a bandwidth of 20 MHz (BW=20 MHz).
To prevent radiation to adjacent bands, guard bands where signals
are not transmitted are arranged at the opposite ends.
[0006] Sub-frames #0 and #5 include the P-SCH, S-SCH and broadcast
information channel as described previously, and the mobile station
apparatus calculates correlation of a reception signal with replica
signals of a plurality of sequences of the primary synchronization
channel P-SCH in the time domain, thereby establishes slot
synchronization (step 1), further calculates correlation of a
reception signal with a plurality of replica signals of the
secondary synchronization channel S-SCH in the time domain or
frequency domain, and establishes frame synchronization using the
sequence of the obtained secondary synchronization channel S-SCH,
while identifying a physical cell ID (Identification:
identification information) Nid (0.ltoreq.Nid.ltoreq.503) to
identify the base station apparatus also using the sequence of the
P-SCH that is previously detected (step 2). The aforementioned two
steps are called a cell search procedure. Subsequently, the mobile
station apparatus demodulates the broadcast information channel,
and is thereby capable of acquiring primary parameters such as the
number of transmission antenna ports.
[0007] FIGS. 7A to 7C are diagrams showing details of a single
resource block. FIGS. 7A to 7C show positions of reference signals
(also referred to as pilot signals) of each antenna port when the
number of transmission antenna ports is "1", "2" or "4",
respectively. The reference signal is a known signal used in
demodulating a signal, and a usage sequence and arrangement pattern
are uniquely designated by physical cell ID Nid of the base station
apparatus. FIG. 7A shows the arrangement when (Nid mod 6)=0, and
when (Nid mod 6)=S, positions are shifted regularly inside the
resource block by S subcarriers from the arrangement of FIG. 7A in
the direction in which frequencies are higher.
[0008] FIG. 8 contains diagrams selectively showing only
arrangements of antenna port 1 when the number of antenna ports is
"4". As shown in FIG. 8, in any physical cell ID, a reference
signal RS1 of the first antenna (Ant 1) and reference signal RS2 of
the second antenna (Ant 2) are mapped to the first and fifth OFDM
symbols in the resource block, and a reference signal RS3 of the
third antenna and reference signal RS4 of the fourth antenna are
mapped to the second OFDM symbol.
[0009] Each component carrier of A-EUTRA has the frame structure of
EUTRA as shown in FIG. 6 described above, and therefore, the frame
structure of A-EUTRA in which component carriers are consecutively
arranged is as shown in FIG. 9. In addition, herein, the
arrangement includes guard bands of each component carrier, but it
is also possible to remove the guard band when component carriers
are consecutively arranged. In the frame configuration of A-EUTRA
in FIG. 9, signals are transmitted from the base station apparatus
of A-EUTRA.
[0010] FIG. 10 is a diagram illustrating a schematic configuration
of the base station apparatus of A-EUTRA. The base station
apparatus 1000 performs coding of transmission data for each
component carrier in coding sections 101-1 to 101-n. Further, the
apparatus modulates the coded signals in modulation sections 102-1
to 102-n. Furthermore, the apparatus generates synchronization
channels and reference signals in SCH/RS generating sections 103-1
to 103-n, based on the physical cell ID (common to all component
carriers) and generation timing notified from a control section,
described later.
[0011] Multiplexing sections 104-1 to 104-n multiplex signals
modulated in the modulation sections 102-1 to 102-n, and the
synchronization channels and reference signals generated in the
SCH/RS generating sections 103-1 to 103-n on an OFDM-symbol basis.
The component carrier multiplexing section 106 maps a signal
corresponding to a single OFDM symbol multiplexed in the
multiplexing sections 104-1 to 104-n for each component carrier to
the frequency region as shown in FIG. 9. A frequency/time transform
section 107 transforms the signal in the frequency domain
multiplexed in the component carrier multiplexing section 106 into
a signal in the time domain by IFFT computing. A transmission
section 108 converts the digital signal that is transformed into
the signal in the time domain into an analog signal, places the
signal on a carrier wave of a predetermined frequency to perform
power amplification, and transmits the signal. In addition, the
above-mentioned coding section 101-1 to transmission section 108
constitute a transmission processing section.
[0012] Meanwhile, the base station apparatus 1000 converts a signal
received from a mobile station apparatus into a digital baseband
signal in a reception section 110. Further, the base station
apparatus 1000 demodulates signals in demodulation sections 111-1
to 111-n for each component carrier, and decodes the demodulated
signals in decoding sections 112-1 to 112-n. In addition, the
above-mentioned reception section 110 to decoding section 112-n
constitute a reception processing section.
[0013] The control section 113 controls each component of the
above-mentioned transmission processing section and reception
processing section. An upper layer 115 outputs a transmission
signal to the above-mentioned transmission processing section,
receives a reception signal from the reception processing section,
and outputs control information to the control section 113. By
using such a base station apparatus 1000, signals of EUTRA are
generated in the coding sections 101-1 to 101-n, modulation
sections 102-1 to 102-n, SCH/RS generating sections 103-1 to 103-n,
and multiplexing sections 104-1 to 104-n for each component
carrier, and the signals of respective component carriers are
aggregated in the component carrier multiplexing section 106, and
transmitted as a signal of A-EUTRA.
[0014] Herein, to efficiently use power amplification performed in
the transmission section 108 in the base station apparatus 1000, it
is generally desirable to reduce the Peak to Average Power Ratio
(PAPR) of a transmission signal to a low level. Since each
component carrier has a different frequency band, the physical cell
ID of each component carrier may be a different ID or the same
ID.
[0015] However, since the reference signal described previously is
uniquely generated from the physical cell ID, when the same ID is
used in each component carrier, as shown in FIG. 9, the same signal
is inserted periodically in OFDM symbols of A-EUTRA including the
reference signal. When the same signal is inserted periodically in
OFDM signal generation, there is a characteristic that the PAPR
increases as the number of times the signal is periodically
inserted increases.
[0016] Therefore, in Non-patent Document 2, it is proposed that a
different ID is used in each component carrier to prevent the same
signal from being inserted periodically, and that the PAPR is
thereby kept low (Non-patent Document 2 uses Cubic Metric (CM) that
is the same indicator as the PAPR.)
[0017] The following table shows an example of CM values of OFDM
symbols including reference signals in the case of using the same
physical cell ID in component carriers of n=1 to 5, and CM values
in the case of using different physical cell IDs. In addition, as
the conditions, "0" is used as the same physical cell ID, and "0",
"1", "2" "3", and "4" are used as different physical cell IDs.
Further, a single transmission antenna is used, and the signal
power other than the reference signal is set at "0".
TABLE-US-00001 TABLE 1 n = 1 n = 2 n = 3 n = 4 n = 5 Same 4.00 6.55
8.53 10.14 11.43 Physical Cell ID Different 4.00 3.75 3.81 3.92
3.93 Physical Cell ID
[0018] As shown in the aforementioned table, it is confirmed that
the CM is kept low by allocating different physical cell IDs to
component carriers.
PRIOR ART DOCUMENT
Patent Document
[0019] Patent Document 1: Japanese Unexamined Patent Publication
NO. 2006-165781
Non-Patent Document
[0019] [0020] Non-patent Document 1: 3GPP TS36.213, V8.3.0 (2008
May),Technical Specification Group Radio Access Network; Evolved
Universal Terrestrial Radio Access (E-UTRA); Physical layer
procedures (Release 8).
http://www.3gpp.org/ftp/Specs/html-info/36213.htm [0021] Non-patent
Document 2: 3GPP TSG RAN WG1 #55, R1-084195, "Issues on the
physical cell ID allocation to the aggregated component carriers",
LG Electronics [0022] Non-patent Document 3: 3GPP TSG RAN WG1 #55,
R1-084196, "Initial Access Procedure in LTE-Advanced", LG
Electronics [0023] Non-patent Document 4: 3GPP TSG RAN WG1 #55bis,
R1-090281, "Resolving CM and Cell ID Issues Associated with
Aggregated Carriers", Texas Instruments
DISCLOSURE OF INVENTION
Problems to be Solved by the Invention
[0024] However, when a mobile station apparatus of A-EUTRA is
assigned resources of a plurality of component carriers, the
apparatus needs to perform processing dependent on the physical
cell ID for each component carrier, for example, scramble release
of the downlink signal, identification of the position and code of
the reference signal, etc. and as shown in Non-patent Document 1,
when different physical cell IDs are used for each component
carrier, needs to perform processing varying with component
carriers. In contrast thereto, when the same physical cell ID is
used for each component carrier, the apparatus is capable of
performing the common processing for each component carrier, and it
is possible to simplify the processing.
[0025] Further, as shown in Non-patent Document 3, in the case that
downlink and uplink are not in a one-to-one correspondence with
each other, and that a single uplink is shared among a plurality of
downlinks (in Asymmetric Carrier aggregation), the correspondence
is made ease by giving the same physical cell ID to downlink
component carriers sharing the uplink.
[0026] Furthermore, in Patent Document 1, the information is
divided into clusters to perform phase control on a cluster basis,
it is thereby intended to reduce the PAPR, but any method suitable
for A-EUTRA is not described. Moreover, in Non-patent Document 4,
it is proposed to reduce the CM by performing predetermined sign
inversion for each component carrier corresponding to the number of
aggregated component carriers.
[0027] The invention was made in view of such circumstances, and it
is an object of the invention to provide a base station apparatus,
mobile station apparatus and mobile communication system for
enabling the PAPR to be kept low even when the same physical cell
ID is used in all or part of component carriers.
Means for Solving the Problem
[0028] (1) To achieve the above-mentioned object, the invention
took measures as described below. In other words, a base station
apparatus of the invention is a base station apparatus that
combines a plurality of component carriers to transmit, and is
characterized by having a phase rotation section that provides
phase rotation for each component carrier, and a transmission
section that transmits the component carrier provided with the
phase rotation to a mobile station apparatus, where an amount of
the phase rotation is determined based on a physical cell ID common
to component carriers.
[0029] Thus, phase rotation is provided for each component carrier,
the phase rotation amount is determined based on the physical cell
ID common to component carriers, and therefore, even when the same
physical cell ID is used in component carriers, it is possible to
maintain compatibility with EUTRA while suppressing increases in
PAPR (CM), and to perform propagation path compensation in A-EUTRA.
By this means, it is possible to make power amplification in the
transmission section efficient. Further, when the mobile station
apparatus performs the processing (for example, scramble release of
the downlink signal, identification of the position and code of the
reference signal, etc.) dependent on the physical cell ID, the
mobile station apparatus is capable of performing the common
processing for each component carrier, and it is possible to
simplify the processing. Furthermore, also at the time of
Asymmetric Carrier aggregation, it is possible to provide downlink
component carriers sharing uplink with the same physical cell
ID.
[0030] (2) Further, the base station apparatus of the invention is
characterized by further having a physical cell ID/phase rotation
amount correspondence table that associates a phase rotation amount
which is beforehand set based on a CM (Cubic Metric) value with the
physical cell ID, where the phase rotation section provides phase
rotation for each component carrier based on the physical cell
ID/phase rotation amount correspondence table.
[0031] Thus, the base station apparatus is further provided with
the physical cell ID/phase rotation amount correspondence table
that associates an amount of phase rotation which is beforehand set
based on a CM (Cubic Metric) value with the physical cell ID, the
phase rotation section provides phase rotation for each component
carrier based on the physical cell ID/phase rotation amount
correspondence table, and it is thereby possible to use an optimal
phase rotation amount for each physical cell ID, and to make the
processing efficient.
[0032] (3) Furthermore, the base station apparatus of the invention
is characterized in that the phase rotation section has a sign
inverting section that inverts the sign, and a replacing section
that replaces a real part and an imaginary part of an input signal
with each other.
[0033] Thus, the phase rotation section is provided with the sign
inverting section that inverts the sign, and the replacing section
that replaces a real part and an imaginary part of an input signal
with each other, and it is thereby possible to simplify the
equipment configuration (circuit configuration), and to maintain
good PAPR characteristics.
[0034] (4) Moreover, a base station apparatus of the invention is a
base station apparatus that combines a plurality of component
carriers to transmit, and is characterized by having a phase
rotation section that provides phase rotation for each component
carrier, a CM calculating section that calculates a CM value when a
physical cell ID is changed in any one of the component carriers, a
control section that sets the phase rotation section for an amount
of phase rotation based on the CM value, and a transmission section
that transmits the component carrier provided with the phase
rotation to a mobile station apparatus.
[0035] Thus, the base station apparatus provides phase rotation for
each component carrier, calculates a CM value when the physical
cell ID is changed in any one of the component carriers, and sets
the phase rotation section for a phase rotation amount based on the
CM value, and therefore, even when the physical cell ID of the
component carrier is set and changed individually, it is possible
to make power amplification in the transmission section
efficient.
[0036] (5) Further, the base station apparatus of the invention is
characterized in that the CM value is a value when a transmission
signal is a reference signal of each component carrier, primary
synchronization channel, secondary synchronization channel,
broadcast information channel or a combination thereof.
[0037] Thus, the CM value is a value when a transmission signal is
a reference signal of each component carrier, primary
synchronization channel, secondary synchronization channel,
broadcast information channel or a combination thereof, and it is
made ease grasping the phase rotation amount such that the CM value
is optimal. In other words, when data except the reference signal
is included, data varies with component carriers, and the CM value
is thereby a good value, but only in the value, there is a case
that it is difficult to grasp the effect of providing the phase
rotation. Therefore, the CM value is used when a transmission
signal is a reference signal of each component carrier, primary
synchronization channel, secondary synchronization channel,
broadcast information channel or a combination thereof.
[0038] (6) Moreover, a base station apparatus of the invention is a
base station apparatus that combines a plurality of component
carriers to transmit, and is characterized by having a phase
rotation section that provides phase rotation for each component
carrier, and a transmission section that transmits the component
carrier provided with the phase rotation to a mobile station
apparatus, where an amount of the phase rotation is determined
based on a physical cell ID, while being changed based on the
physical cell ID at certain time intervals.
[0039] Thus, since the phase rotation amount is determined based on
the physical cell ID, while being changed based on the physical
cell ID at certain time intervals, signals of adjacent cells
(having different physical cell IDs) rotate in phase independently
of each other with time, and it is possible to randomize
interference.
[0040] (7) Further, the base station apparatus of the invention is
characterized by further having a physical cell ID/phase rotation
amount correspondence table that associates the physical cell ID
with each amount of phase rotation of the component carrier, and a
physical cell ID/phase rotation offset amount correspondence table
that associates the physical cell ID with a phase rotation offset
amount in the time domain to store, where the phase rotation
section provides phase rotation for each component carrier based on
the physical cell ID/phase rotation amount correspondence table and
the physical cell ID/phase rotation offset amount correspondence
table.
[0041] Thus, the base station apparatus is further provided with
the physical cell ID/phase rotation amount correspondence table
that associates the physical cell ID with each phase rotation
amount of the component carrier, and the physical cell ID/phase
rotation offset amount correspondence table that associates the
physical cell ID with a phase rotation offset amount in the time
domain to store, the phase rotation section performs phase rotation
for each component carrier based on the physical cell ID/phase
rotation amount correspondence table and the physical cell ID/phase
rotation offset amount correspondence table, signals of adjacent
cells (having different physical cell IDs) thereby rotate in phase
independently of each other with time, and it is possible to
randomize interference and make the processing efficient.
[0042] (8) Furthermore, the base station apparatus of the invention
is characterized by changing a basis for the amount of the phase
rotation corresponding to the number of component carriers to
combine.
[0043] Thus, since the basis for the phase rotation amount is
changed corresponding to the number of aggregated component
carriers, it is possible to enhance PAPR (CM) characteristics while
suppressing increases in the circuit scale.
[0044] (9) Further, a mobile station apparatus of the invention is
a mobile station apparatus that performs wireless communications
with the above-mentioned base station apparatus, and is
characterized by providing a signal received from the base station
apparatus with inverse phase rotation to phase rotation provided in
the base station apparatus.
[0045] Thus, the mobile station apparatus provides a signal
received from the base station apparatus with inverse phase
rotation to phase rotation provided in the base station apparatus,
and is thereby capable of performing propagation path compensation
with high accuracy. By this means, for example, when a mobile
station apparatus of A-EUTRA performs propagation path compensation
exceeding the period of count-up, the mobile station apparatus
removes a phase rotation offset added in the base station apparatus
before the propagation path compensation section, and is thereby
capable of performing propagation path compensation with high
accuracy.
[0046] (10) Furthermore, the mobile station apparatus of the
invention is characterized by providing the inverse phase rotation
based on an amount of phase rotation that is beforehand notified
from the base station apparatus using an upper control signal.
[0047] Thus, the mobile station apparatus provides the inverse
phase rotation based on an amount of phase rotation that is
beforehand notified from the base station apparatus using an upper
control signal, thereby restores the phase rotation added in the
base station apparatus by inverse phase rotation based on the
notified phase rotation amount, and is capable of performing
propagation path compensation across component carriers.
[0048] (11) Still furthermore, the mobile station apparatus of the
invention is characterized by having a phase difference determining
section that determines an amount of phase rotation of each
component carrier from a phase difference between adjacent
component carriers, and providing the inverse phase rotation based
on the amount of phase rotation determined in the phase difference
determining section.
[0049] Thus, the mobile station apparatus determines the phase
rotation amount of each component carrier from the phase difference
between adjacent component carriers, restores the phase rotation
added in the base station apparatus by inverse phase rotation based
on the determined phase rotation amount, and is capable of
performing propagation path compensation across component
carriers.
[0050] (12) Moreover, a mobile station apparatus of the invention
is a mobile station apparatus that performs wireless communications
with the above-mentioned base station apparatus, and is
characterized by having a physical cell ID/phase rotation amount
correspondence table that associates an amount of phase rotation
that is beforehand set based on a CM value with the physical cell
ID, acquiring an amount of phase rotation from the physical cell
ID/phase rotation amount correspondence table, and a physical cell
ID of a base station apparatus to connect, and providing a signal
received from the base station apparatus with inverse phase
rotation to phase rotation provided in the base station
apparatus.
[0051] Thus, the mobile station apparatus acquires an amount of
phase rotation from the physical cell ID/phase rotation amount
correspondence table, and a physical cell ID of a base station
apparatus to connect, thereby restores the phase rotation added in
the base station apparatus by inverse phase rotation based on the
acquired phase rotation amount, and is capable of performing
propagation path compensation across component carriers.
[0052] (13) Further, a mobile station apparatus of the invention is
a mobile station apparatus that performs wireless communications
with the above-mentioned base station apparatus, and is
characterized by providing a signal received from the base station
apparatus with inverse phase rotation to phase rotation provided in
the base station apparatus on a basis for an amount of phase
rotation corresponding to the number of combined component
carriers.
[0053] Thus, the mobile station apparatus provides a signal
received from the base station apparatus with inverse phase
rotation to phase rotation provided in the base station apparatus
on a basis of the amount of phase rotation corresponding to the
number of aggregated component carriers, and is thereby capable of
decreasing determination errors in determining the amount of phase
rotation.
[0054] (14) Moreover, a mobile communication system of the
invention is characterized by being comprised of any one of base
station apparatuses described above, a mobile station apparatus
supporting EUTRA (Evolved Universal Terrestrial Radio Access), and
a mobile station apparatus supporting A-EUTRA (Advanced EUTRA).
[0055] According to this configuration, phase rotation is provided
for each component carrier, the phase rotation amount is determined
based on a physical cell ID common to component carriers, and
therefore, even when the same physical cell ID is used in the
component carriers, it is possible to maintain compatibility with
EUTRA while suppressing increases in PAPR (CM), and perform
propagation path compensation in A-EUTRA. By this means, it is
possible to make power amplification in the transmission section
efficient. Further, when the mobile station apparatus performs the
processing (for example, scramble release of the downlink signal,
identification of the position and code of the reference signal,
etc.) dependent on the physical cell ID, the mobile station
apparatus is capable of performing the common processing for each
component carrier, and it is possible to simplify the processing.
Furthermore, also at the time of Asymmetric Carrier aggregation, it
is possible to provide downlink component carriers sharing uplink
with the same physical cell ID.
Advantageous Effect of the Invention
[0056] According to the invention, phase rotation is provided for
each component carrier, the phase rotation amount is determined
based on a physical cell ID common to component carriers, and
therefore, even when the same physical cell ID is used in the
component carriers, it is possible to maintain compatibility with
EUTRA while suppressing increases in PAPR (CM), and perform
propagation path compensation in A-EUTRA. By this means, it is
possible to make power amplification in the transmission section
efficient. Further, when the mobile station apparatus performs the
processing (for example, scramble release of the downlink signal,
identification of the position and code of the reference signal,
etc.) dependent on the physical cell ID, the mobile station
apparatus is capable of performing the common processing for each
component carrier, and it is possible to simplify the processing.
Furthermore, also at the time of Asymmetric Carrier aggregation, it
is possible to provide downlink component carriers sharing uplink
with the same physical cell ID. Moreover, also when physical cell
IDs of part of component carriers are different IDs, it is
similarly possible to maintain compatibility with EUTRA while
suppressing increases in PAPR (CM), and to perform propagation path
compensation in A-EUTRA.
BRIEF DESCRIPTION OF DRAWINGS
[0057] FIG. 1 is a block diagram illustrating a schematic
configuration of a base station apparatus according to this
Embodiment;
[0058] FIG. 2A is a block diagram illustrating a schematic
configuration of a base station apparatus according to Embodiment
2;
[0059] FIG. 2B is a block diagram illustrating a schematic
configuration of a phase rotation section;
[0060] FIG. 3 is a block diagram illustrating a schematic
configuration of a base station apparatus according to Embodiment
3;
[0061] FIG. 4 is a block diagram illustrating a schematic
configuration of a base station apparatus according to this
Embodiment;
[0062] FIG. 5 is a diagram illustrating a schematic configuration
of a reception processing section of an A-EUTRA mobile station
apparatus according to this Embodiment;
[0063] FIG. 6 is a diagram showing an example of a configuration of
a radio frame in EUTRA;
[0064] FIG. 7A is a diagram showing details of a single resource
block;
[0065] FIG. 7B is another diagram showing details of a single
resource block;
[0066] FIG. 7C is still another diagram showing details of a single
resource block;
[0067] FIG. 8 contains diagrams selectively showing only
arrangements of antenna port 1 when the number of antenna ports is
"4";
[0068] FIG. 9 is a diagram illustrating a frame configuration of
A-EUTRA in which component carriers are consecutively arranged;
[0069] FIG. 10 is a diagram illustrating a schematic configuration
of a base station apparatus of A-EUTRA;
[0070] FIG. 11 is a diagram illustrating an arrangement of
reference signals used in detecting a phase difference between
component carriers; and
[0071] FIG. 12 is a diagram showing another example of the
reception processing section of the A-EUTRA mobile station
apparatus according to this Embodiment.
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1
[0072] A base station apparatus of A-EUTRA according to Embodiment
1 of the invention will be described below with reference to
drawings. FIG. 1 is a block diagram illustrating a schematic
configuration of a base station apparatus according to this
Embodiment. The base station apparatus 100 in this Embodiment
performs coding of transmission data for each component carrier in
coding sections 101-1 to 101-n. Further, the apparatus modulates
the coded signals in modulation sections 102-1 to 102-n.
Furthermore, the apparatus generates synchronization channels and
reference signals in SCH/RS generating sections 103-1 to 103-n,
based on the physical cell ID (common to all component carriers)
and generation timing notified from a control section, described
later.
[0073] Multiplexing sections 104-1 to 104-n multiplex signals
modulated in the modulation sections 102-1 to 102-n, and the
synchronization channels and reference signals generated in the
SCH/RS generating sections 103-1 to 103-n on an OFDM-symbol basis.
Phase rotation sections 105-1 to 105-n rotate the signals
multiplexed in the multiplexing sections 104-1 to 104-n by a phase
designated by the control section, described later. The component
carrier multiplexing section 106 maps the signal corresponding to a
single OFDM symbol subjected to phase rotation in the phase
rotation sections 105-1 to 105-n for each component carrier to the
frequency region as shown in FIG. 9. A frequency/time transform
section 107 transforms the signal in the frequency domain
multiplexed in the component carrier multiplexing section 106 into
a signal in the time domain by IFFT computing. A transmission
section 108 converts the digital signal that is transformed into
the signal in the time domain into an analog signal, places the
signal on a carrier wave of a predetermined frequency to perform
power amplification, and transmits the signal. In addition, the
above-mentioned coding section 101-1 to transmission section 108
constitute a transmission processing section.
[0074] Meanwhile, the base station apparatus 100 converts a signal
received from a mobile station apparatus into a digital baseband
signal in a reception section 110. Further, the base station
apparatus demodulates signals in demodulation sections 111-1 to
111-n for each component carrier, and decodes the demodulated
signals in decoding sections 112-1 to 112-n. In addition, the
above-mentioned reception section 110 to decoding section 112-n
constitute a reception processing section.
[0075] The control section 113 controls each component of the
above-mentioned transmission processing section and reception
processing section. A physical cell ID/phase rotation amount
correspondence table 114 associates the physical cell ID with each
phase rotation amount of the component carrier to store. An upper
layer 115 outputs a transmission signal to the above-mentioned
transmission processing section, receives a reception signal from
the reception processing section, and outputs control information
to the control section 113.
[0076] In other words, the base station apparatus 100 adopts the
configuration obtained by adding the phase rotation sections 105-1
to 105-n and physical cell ID/phase rotation amount correspondence
table 114 to the configuration of the conventional base station
apparatus. In the above-mentioned base station apparatus 100,
component carrier transmission signals generated up to the
multiplexing sections 104-1 to 104-n are given individual phase
rotation for each component carrier in the phase rotation sections
105-1 to 105-n, respectively. Each phase rotation amount is
designated by the control section 113 based on the physical cell
ID/phase rotation amount correspondence table 114. The signal
subjected to phase rotation for each component carrier is placed on
a subcarrier of an A-EUTRA frame in the component carrier
multiplexing section 106 as in the conventional case, transformed
into a signal in the time domain in the frequency/time transform
section 107, and is transmitted from the transmission section
108.
[0077] The following table shows an example of CM values of OFDM
symbols including reference signals when phase rotation is not
performed in component carriers of n=1 to n=5, and CM values when
phase rotation is provided. In addition, as the conditions, the
physical cell ID is set at "0" and "18", a single transmission
antenna is used, and the signal power other than the reference
signal is set at "0". Phase rotation A in the table is in the case
that the phase rotation amount of each component carrier is (0
degree, 180 degrees, 0 degree, -36 degrees, -18 degrees), phase
rotation B is in the case that the phase rotation amount of each
component carrier is (0 degree, -72 degrees, -108 degrees, 0
degree, 180 degrees), and Phase rotation C is in the case that the
phase rotation amount of each component carrier is (0 degree, -36
degrees, -72 degrees, -108 degrees, -144 degrees).
TABLE-US-00002 TABLE 2 n = 1 n = 2 n = 3 n = 4 n = 5 Cell ID 0 No
Phase 4.00 6.55 8.53 10.14 11.43 Rotation Phase 4.00 6.57 5.33 5.39
5.39 Rotation A Phase 4.00 6.54 5.61 5.57 6.22 Rotation B Phase
4.00 6.54 7.12 7.85 7.91 Rotation C Cell ID 18 No Phase 4.02 6.51
8.55 10.09 11.42 Rotation Phase 4.02 6.49 5.38 5.33 5.32 Rotation A
Phase 4.02 6.51 5.52 5.50 6.15 Rotation B Phase 4.02 6.51 7.03 7.79
7.74 Rotation C
[0078] From this table, it is understood that it is possible to
reduce the CM by providing phase rotation for each component
carrier. Further, from comparison between phase rotation A and B,
it is understood that the difference arises in the CM value also by
setting of phase rotation amount. Therefore, the base station
apparatus in this Embodiment beforehand calculates optimal phase
rotation amounts for each physical cell ID to refer to as the
table.
[0079] The following table shows an example of CM calculation
results when a random QPSK signal is input as data other than the
reference signal. Herein, the case is assumed that the power of the
reference signal is boosted by 3 dB than the other signal.
TABLE-US-00003 TABLE 3 n = 1 n = 2 n = 3 n = 4 n = 5 Cell ID 0 No
Phase 4.06 4.40 5.04 5.29 6.03 Rotation Phase 4.06 4.45 4.28 4.09
4.12 Rotation A Phase 4.06 4.54 4.32 4.10 4.47 Rotation B Phase
4.06 4.50 4.56 4.64 4.74 Rotation C Cell ID 18 No Phase 4.30 4.77
5.19 5.47 6.16 Rotation Phase 4.30 4.96 4.32 4.13 4.06 Rotation A
Phase 4.30 4.56 4.36 4.22 4.31 Rotation B Phase 4.30 4.66 4.75 4.66
4.67 Rotation C
[0080] When the data is inserted, since the data varies with
component carriers normally, the CM values are improved as compared
with the case of only the reference signal, but from the table, it
is understood that the CM values are further improved by phase
rotation also when the data is inserted. Further, from two tables
shown in Embodiment 1, it is understood that phase rotation
(herein, C) poor in characteristics only in the reference signal is
poor in characteristics also in the case of including the data.
Therefore, in this Embodiment, as phase rotation amounts beforehand
set in the physical cell ID/phase rotation amount correspondence
table, selected are combinations such that the CM value is the best
in the case where only reference signals corresponding to the
physical cell ID are arranged. In addition, it is also possible to
generate a table by calculating the CM value using the other signal
such as the primary synchronization channel, secondary
synchronization channel and broadcast information channel that is
the same for each component carrier.
[0081] Described next is the operation of the mobile station
apparatus of EUTRA and the mobile station apparatus of A-EUTRA in a
system using the above-mentioned base station apparatus 100. The
mobile station apparatus of EUTRA is capable of receiving only a
single component carrier in a frame of A-EUTRA. Herein, in a single
component carrier in this Embodiment, all subcarriers are provided
with uniform phase rotation. Therefore, the mobile station
apparatus receiving only the component carrier is capable of
compensating for phase rotation provided in the base station
apparatus in performing propagation path compensation, without
distinguishing from phase rotation in the propagation path. This is
the same as in all other component carriers, and the mobile station
apparatus of EUTRA that connects with the base station apparatus
using each component carrier is capable of performing
communications without requiring additional processing according to
the invention.
[0082] Next, the mobile station apparatus of A-EUTRA concurrently
receives signals of a plurality of component carriers, and
therefore, when different phase rotation is added in consecutive
component carriers, is not capable of performing propagation path
compensation across the component carriers without any
processing.
[0083] As a method of solving the above-mentioned problem, the
following methods are conceived.
(1) The mobile station apparatus does not perform propagation path
compensation across component carriers. In other words, the
apparatus performs propagation path compensation for each component
carrier. It is assumed that the mobile station apparatus is
assigned a plurality of component carriers with discrete
frequencies, and therefore, it is possible to perform propagation
path compensation individually on consecutive component carriers.
(2) For a mobile station apparatus assigned a plurality of
component carriers, a phase rotation amount for each component
carrier is beforehand included in an upper control signal (for
example, information to notify as system information (SIB)), and
the mobile station apparatus restores the added phase rotation by
inverse phase rotation based on the information, and performs
propagation path compensation across component carriers. (3) A
mobile station apparatus is also provided with the same physical
cell ID/phase rotation amount correspondence table as in the base
station apparatus, and acquires phase rotation amounts of all the
component carriers from the table based on the physical cell ID
acquired in one component carrier. (4) The phase rotation amount of
each component is limited to only two kinds, 0 degree and 180
degrees. Then, as shown in FIG. 11, using replicas (reference
signals generated in the mobile station apparatus that uniquely
correspond to the physical cell ID) of m reference signals from the
edge of each component carrier and an actual reception signal, a
mobile station apparatus obtains phase rotation amounts at the
positions, compares the difference of the phase rotation amount
between the adjacent component carrier, and thereby estimates that
the difference of the phase rotation amount between the adjacent
component carriers is 0 degree or 180 degrees.
[0084] As a specific example of above-mentioned method (4), in FIG.
11, it is assumed that r1 is a reference signal included in a
single OFDM symbol of component carrier #1 received in the mobile
station apparatus, r2 is a reference signal of component carrier
#2, r3 is a reference signal of component carrier #3, and that R1,
R2 or R3 is a reference signal generated in the mobile station
apparatus that uniquely corresponds to the physical cell ID of each
component carrier. When the physical cell ID of each component
carrier is the same, R1=R2=R3. Further, it is assumed that "M" is
the number of reference signals of each component carrier included
in a single OFDM symbol.
[0085] First, obtained is a phase difference between each of m
received reference signals from the edge of the component carrier
and a replica, and an average phase difference P of m signals is
obtained. For example, using conj ( ) as the function of obtaining
a complex conjugate, P1 of FIG. 11 is obtained using the following
equation.
P1=(.SIGMA..sub.k=M-m+1.sup.Mr1(k).times.conj(R1(k)))/m [Eq. 1]
Similarly, P2, P3 and P4 are obtained.
[0086] Next, by comparing phase difference P1 with P2, and P3 with
P4, it is possible to obtain the phase difference between component
carriers #1 and #2, and the phase difference between component
carriers #2 and #3. For example, it is possible to determine that
the phase difference is 0 degree when the phase difference between
P1 and P2 ranges from -90 degrees to 90 degrees, and that the phase
difference is 180 degrees when the phase difference between P1 and
P2 is less than -90 degrees or more than 90 degrees.
[0087] Herein, the phase rotation amounts are assumed to be 0
degree and 180 degrees, and assuming that 90 degrees are a basis of
the phase rotation amount, it is possible to make the determination
of the above-mentioned phase difference so that the phase
difference is 0 degree when the phase difference ranges from -45
degrees to 45 degrees, the phase difference is 90 degrees when the
phase difference ranges from 45 degrees to 135 degrees, the phase
difference is 180 degrees when the phase difference ranges from 135
degrees to 225 degrees, and that the phase difference is 270 degree
(-90 degrees) when the phase difference ranges from 225 degrees to
315 degrees.
[0088] In addition, in the specific example, the phase difference
is calculated by averaging on an OFDM-symbol basis (frequency
domain), and it is possible to obtain a more accurate phase
difference by averaging in the time domain or in both time and
frequency domain.
[0089] FIG. 12 is a diagram illustrating a schematic configuration
of a reception processing section of the A-EUTRA mobile station
apparatus that performs the above-mentioned processing. The
reception processing section 1200 of the mobile station apparatus
converts a reception signal into a baseband signal in a reception
section 1201. A synchronization processing section 1202 detects a
synchronization channel from the signal received in the reception
section 1201, and performs synchronization processing. A
time/frequency transform section 1203 transforms the signal in the
time domain into a signal in the frequency domain at timing
synchronized in the synchronization processing section 1202. A
component carrier dividing section 1204 divides the signal in the
frequency domain transformed in the time/frequency transform
section 1203 into signals of respective component carriers.
Further, the section 1203 outputs reference signals obtained from
the result of division to a phase difference calculating section
1211.
[0090] Phase rotation sections 1205-1 to 1205-n provide the signals
of respective component carriers divided in the component carrier
dividing section 1204 with phase rotation designated from a control
section, described later. Propagation path compensation sections
1206-1 to 1206-n perform propagation path compensation based on
reference signals included in the signals undergoing phase rotation
in the phase rotation sections 1205-1 to 1205-n. Demodulation
sections 1207-1 to 1207-n demodulate the signals undergoing
propagation path compensation in the propagation path compensation
sections 1206-1 to 1206-n. Decoding sections 1208-1 to 1208-n
decode the demodulated signals. An upper layer 1209 receives the
decoded signals.
[0091] The control section 1210 controls each component. Further,
the control section 1210 outputs the physical cell ID and position
information of reference signals inside the frame to the phase
difference calculating section 1211. The phase difference
calculating section 1211 generates replicas of reference signals
based on the reference signals input from the component carrier
dividing section 1204, and the physical cell ID and position
information of reference signals inside the frame input from the
control section 1210. Then, the section 1211 calculates a phase
difference between the replica and the reference signal to output
to the phase difference determining section 1212. The phase
difference calculating section 1212 determines a phase rotation
amount of each component carrier in transmission from a phase
difference between adjacent component carriers to notify the
control section 1210.
[0092] Described next is the operation of the reception processing
section 1200 of the mobile station apparatus configured as
described above. First, the reception section 1201 converts a
received signal into a digital baseband signal to input to the
synchronization processing section 1202. The synchronization
processing section 1202 detects the frequency including the
synchronization channel to acquire synchronization, and acquires
physical cell ID information from the synchronization channel.
Further, from the primary broadcast channel, the section 1202
acquires information such as the antenna information and system
frame number required for communications. The acquired information
is sent to the upper layer 1209. The upper layer 1209 notifies the
control section 1210 of information required for subsequent signal
demodulation.
[0093] The control section 1210 controls each section based on the
control information from the upper layer 1209. An output from the
reception section 1201 is subjected to FFT transform on an
OFDM-symbol basis in the time/frequency transform section 1203
based on the timing information from the control section 1210, and
is transformed into a signal in the frequency domain. The
transformed signal in the frequency domain is input to the
component carrier dividing section 1204. The component carrier
dividing section 1204 divides the signal in the frequency domain
into information for each component carrier to output to the phase
difference calculating section 1211. Based on the physical cell ID
notified from the control section 1210, the phase difference
calculating section 1211 calculates a phase difference between a
replica of the reference signal and the reference signal of each
component carrier input from the component carrier dividing section
1204.
[0094] The calculated phase difference information of each
component carrier is notified to the phase difference determining
section 1212. The phase difference determining section 1212
determines a phase difference between adjacent component carriers
from the technique as described above using the phase difference
information of each component carrier input from the phase
difference calculating section 1211, and notifies the control
section 1210 of the phase difference. Based on the phase difference
information input from the control section 1210, the signal input
to each of the phase rotation sections 1205-1 to 1205-n is provided
with inverse phase rotation to phase rotation provided in the base
station apparatus. The phase-rotated signals are input to the
propagation path compensation sections 1206-1 to 1206-n. The
propagation path compensation sections 1206-1 to 1206-n perform
propagation path compensation based on the reference signals
included in the reception signal. The signals subjected to
propagation path compensation are demodulated in the demodulation
sections 1207-1 to 1207-n, decoded in the decoding sections 1208-1
to 1208-n, and notified to the upper layer 1209.
[0095] By using the above-mentioned mobile station apparatus, it is
possible to demodulate signals provided with phase rotation. In
addition, in the above-mentioned description, propagation path
compensation is performed for each component carrier, and
naturally, it is also possible to perform propagation path
compensation using reference signals of a plurality of component
carriers.
[0096] In any of the methods, when the same physical cell ID is
used in component carriers, by using the base statin apparatus of
this Embodiment, it is possible to maintain compatibility with
EURTA while suppressing increases in PAPR (CM), and to perform
propagation path compensation in A-EUTRA. By this means, the base
station apparatus 100 is capable of making power amplification in
the transmission section 108 efficient, and when the mobile station
apparatus performs the processing (for example, scramble release of
the downlink signal, identification of the position and code of the
reference signal, etc.) dependent on the physical cell ID, the
mobile station apparatus is capable of performing the common
processing for each component carrier, and of simplifying the
processing.
[0097] Further, also at the time of Asymmetric Carrier aggregation,
it is possible to provide downlink component carriers sharing
uplink with the same physical cell ID. Further, the mobile station
apparatus acquires the phase rotation amount provided in each
component carrier using the above-mentioned methods (2) to (4) for
propagation path compensation, and is thereby capable of using in
uses other than propagation path compensation, for example, in
measuring the channel quality, and in signal processing in the case
called CoMP where a plurality of base station apparatuses and relay
station apparatuses coordinate to transmit a signal to a single
mobile station apparatus.
Embodiment 2
[0098] A base station apparatus of A-EUTRA according to Embodiment
2 of the invention will be described below with reference to
drawings. FIG. 2A is a block diagram illustrating a schematic
configuration of a base station apparatus according to Embodiment
2. The base station apparatus 200 differs from that in Embodiment
1, and is configured by adding only phase rotation sections 105-1
to 105-n to the processing for each component carrier of the
conventional base station apparatus. In other words, the base
station apparatus 200 in this Embodiment performs coding of
transmission data for each component carrier in coding sections
101-1 to 101-n. Further, the apparatus modulates the coded signals
in modulation sections 102-1 to 102-n. Furthermore, the apparatus
generates synchronization channels and reference signals in SCH/RS
generating sections 103-1 to 103-n, based on the physical cell ID
(common to all component carriers) and generation timing notified
from the control section, described later. Multiplexing sections
104-1 to 104-n multiplex signals modulated in the modulation
sections 102-1 to 102-n, and the synchronization channels and
reference signals generated in the SCH/RS generating sections 103-1
to 103-n on an OFDM-symbol basis.
[0099] Phase rotation sections 105-1 to 105-n rotate the signals
multiplexed in the multiplexing sections 104-1 to 104-n by a phase
designated by the control section, described later. FIG. 2B is a
block diagram illustrating a schematic configuration of the phase
rotation section. A sign inverting section 105a performs sign
inversion on the signals input from the multiplexing sections 104-1
to 104-n. A replacing section 105b replaces a real part and an
imaginary part of the input signal with each other.
[0100] The component carrier multiplexing section 106 maps the
signal corresponding to a single OFDM symbol subjected to phase
rotation in the phase rotation sections 105-1 to 105-n for each
component carrier to the frequency region as shown in FIG. 9. The
frequency/time transform section 107 transforms the signal in the
frequency domain multiplexed in the component carrier multiplexing
section 106 into a signal in the time domain by IFFT computing. The
transmission section 108 converts the digital signal that is
transformed into the signal in the time domain into an analog
signal, places the signal on a carrier wave of a predetermined
frequency to perform power amplification, and transmits the signal.
In addition, the above-mentioned coding section 101-1 to
transmission section 108 constitute the transmission processing
section.
[0101] Meanwhile, the base station apparatus 200 converts a signal
received from a mobile station apparatus into a digital baseband
signal in the reception section 110. Further, the base station
apparatus demodulates signals in demodulation sections 111-1 to
111-n for each component carrier, and decodes the demodulated
signals in decoding sections 112-1 to 112-n. In addition, the
above-mentioned reception section 110 to decoding section 112-n
constitute the reception processing section. The control section
113 controls each component of the above-mentioned transmission
processing section and reception processing section. The upper
layer 115 outputs a transmission signal to the above-mentioned
transmission processing section, receives a reception signal from
the reception processing section, and outputs control information
to the control section 113.
[0102] In the above-mentioned base station apparatus, the component
carrier transmission signal generated in each of the multiplexing
sections 104-1 to 104-n is provided with individual phase rotation
for each component carrier in respective one of the phase rotation
sections 105-1 to 105-n. Each phase rotation amount is designated
from among 0 degree, 90 degrees, 180 degrees, and 270 degrees. In
other words, the phase rotation sections 105-1 to 105-n are capable
of being configured by replacing the real part and the imaginary
part of an input signal represented by a complex number, and
inverting the sign. More specifically, in the case of performing
0-degree phase rotation, the input signal is output without any
processing. Meanwhile, in the case of performing 90-degree phase
rotation, the sign of the imaginary part of the input signal is
inverted, the imaginary part is replaced with the real part, and
the input signal is output. Further, in the case of performing
180-degree phase rotation, the sign of the real part of the input
signal is inverted, and the input signal is output. In the case of
performing 270-degree phase rotation, the sign of the real part of
the input signal is inverted, the real part is replaced with the
imaginary part, and the input signal is output.
[0103] The signal subjected to phase rotation for each component
carrier is placed on a subcarrier of an A-EUTRA frame in the
component carrier multiplexing section 106 as in Embodiment 1,
transformed into a signal in the time domain in the frequency/time
transform section 107, and is transmitted from the transmission
section 108.
[0104] The following table shows an example of CM values of OFDM
symbols including reference signals when phase rotation is not
performed in component carriers of n=1 to n=5, and CM values when
phase rotation is provided. In addition, as the conditions, the
physical cell ID is set at "0" and "18", a single transmission
antenna is used, and the signal power other than the reference
signal is set at "0". Phase rotation D in the table is in the case
that the phase rotation amount of each component carrier is (0
degree, 90 degrees, 90 degrees, 0 degree, 180 degrees), and phase
rotation A is the same as in Embodiment 1.
TABLE-US-00004 TABLE 4 n = 1 n = 2 n = 3 n = 4 n = 5 Cell ID 0 No
Phase 4.00 6.55 8.53 10.14 11.43 Rotation Phase 4.00 6.57 5.33 5.39
5.39 Rotation A Phase 4.00 6.58 5.33 5.56 5.99 Rotation D Cell ID
18 No Phase 4.02 6.51 8.55 10.09 11.42 Rotation Phase 4.02 6.49
5.38 5.33 5.32 Rotation A Phase 4.02 6.48 5.38 5.51 5.91 Rotation
D
[0105] From this table, it is understood that it is possible to
also obtain the effect of reducing the CM by providing phase
rotation limited to a 90-degree basis. Therefore, the base station
apparatus in this Embodiment is capable of maintaining the same
PAPR (CM) characteristics as in Embodiment 1, while simplifying the
circuit configuration of the base station apparatus.
[0106] In above-mentioned Embodiments 1 and 2, the example is
described where in calculating a phase rotation amount,
combinations for keeping the CM value low are calculated
irrespective of the number of component carriers. In other words,
in the same physical cell ID, the phase rotation amount
corresponding to the component carrier number does not change when
the number of aggregated component carriers is "2", "3", "4" or
"5". The advantage of this scheme is to enable reductions in the CM
value of a signal transmitted from an unsophisticated base station
apparatus or relay station apparatus, for example, in the case of
installing the unsophisticated base station apparatus or relay
station apparatus inside a cell as extension and transmitting the
same signal as only part (for example, three component carriers) of
component carriers of the basic base station apparatus, for the
purpose of eliminating coverage holes (areas such as a valley
between buildings at which the radio signal does not arrive) of the
basic base station apparatus in the cell in which the number of
aggregated component carriers is four.
[0107] However, when it is possible to use a value different from
the basis base station apparatus as the phase rotation amount in
transmitting from the unsophisticated base station apparatus or
relay station apparatus, an optimal phase rotation amount may be
obtained corresponding to the number of aggregated component
carriers.
Embodiment 3
[0108] A base station apparatus of A-EUTRA according to Embodiment
3 of the invention will be described below with reference to
drawings. In EUTRA or A-EUTRA, the mechanism called a Self
Organized Network (SON) is proposed in which optimization of the
communication system is automatically performed, and it is
considered setting and varying the physical cell ID corresponding
to the circumstances of adjacent cells. In performing optimization
for each component carrier by SON, there is a case that the same
physical cell ID is used among only part of component carriers.
Therefore, this Embodiment describes the base statin apparatus in
the case where the physical cell ID of each component carrier is
automatically determined.
[0109] FIG. 3 is a block diagram illustrating a schematic
configuration of a base station apparatus according to Embodiment
3. The base station apparatus 300 adopts a configuration obtained
by adding a CM calculating section 116 to the configuration of the
conventional base station apparatus. The base station apparatus
performs coding of transmission data for each component carrier in
coding sections 101-1 to 101-n. Further, the apparatus modulates
the coded signals in modulation sections 102-1 to 102-n.
Furthermore, the apparatus generates synchronization channels and
reference signals in SCH/RS generating sections 103-1 to 103-n,
based on the physical cell ID (common to all component carriers)
and generation timing notified from the control section, described
later.
[0110] Multiplexing sections 104-1 to 104-n multiplex signals
modulated in the modulation sections 102-1 to 102-n, and the
synchronization channels and reference signals generated in the
SCH/RS generating sections 103-1 to 103-n on an OFDM-symbol basis.
Phase rotation sections 105-1 to 105-n rotate the signals
multiplexed in the multiplexing sections 104-1 to 104-n by a phase
designated by the control section, described later. The component
carrier multiplexing section 106 maps the signal corresponding to a
single OFDM symbol subjected to phase rotation in the phase
rotation sections 105-1 to 105-n for each component carrier to the
frequency region as shown in FIG. 9. The frequency/time transform
section 107 transforms the signal in the frequency domain
multiplexed in the component carrier multiplexing section 106 into
a signal in the time domain by IFFT computing.
[0111] The CM calculating section 116 calculates a CM of the signal
that is transformed in the frequency/time transform section 107.
The transmission section 108 converts the digital signal that is
transformed into the signal in the time domain into an analog
signal, places the signal on a carrier wave of a predetermined
frequency to perform power amplification, and transmits the signal.
In addition, the above-mentioned coding section 101-1 to
transmission section 108 constitute the transmission processing
section.
[0112] Meanwhile, the base station apparatus 300 converts a signal
received from a mobile station apparatus into a digital baseband
signal in the reception section 110 as the reception processing
section. Further, the base station apparatus demodulates signals in
demodulation sections 111-1 to 111-n for each component carrier,
and decodes the demodulated signals in decoding sections 112-1 to
112-n. In addition, the above-mentioned reception section 110 to
decoding section 112-n constitute the reception processing
section.
[0113] The control section 113 controls each component of the
above-mentioned transmission processing section and reception
processing section. The upper layer 115 outputs a transmission
signal to the above-mentioned transmission processing section,
receives a reception signal from the reception processing section,
and outputs control information to the control section 113.
[0114] When the physical cell ID is determined or changed, the base
station apparatus 300 performs the following operation. First, the
control section 113 notifies the SCH/RS generating sections 103-1
to 103-n of the physical cell ID for each component carrier. The
SCH/RS generating sections 103-1 to 103-n generate reference
signals to output to the multiplexing sections 104-1 to 104-n. The
multiplexing sections 104-1 to 104-n output null signals except the
reference signals to the phase rotation sections 105-1 to 105-n.
The control section 113 notifies different phase rotation amounts
to phase rotation sections 105-1 to 105-n for component carriers of
the same physical cell ID, and designates 0 degree as the phase
rotation amount to phase rotation sections 105-1 to 105-n of
component carriers except the component carriers of the same
ID.
[0115] Each of the phase rotation sections 105-1 to 105-n adds the
phase rotation amount designated by the control section 113 to the
input signal from respective one of the multiplexing sections 104-1
to 104-n. The phase-rotated signals of respective component
carriers are multiplexed in the component carrier multiplexing
section 106, and transformed into a signal in the time domain in
the frequency/time transform section 107.
[0116] An output signal of the frequency/time transform section 107
is input to the CM calculating section 116, and the CM value is
calculated. The calculated CM value is input to the control section
113, and the processing is repeated by changing the phase rotation
amount of component carriers of the same physical cell ID until the
CM value meets a condition. Examples of the condition for the CM
value to meet are as described below.
(1) The CM value falls below a predetermined threshold. (2) The CM
value is the lowest among combinations of the finite number of
phase rotation amounts.
[0117] Further, when all of the combinations of above-mentioned
condition (2) exceed the predetermined threshold, it is conceivable
to change the physical cell ID.
[0118] When the phase rotation amount is set by the aforementioned
processing, as in the base station apparatus of Embodiment 1, the
transmission section 108 performs transmission using the set phase
rotation amount.
[0119] As described above, according to Embodiment 3, even when the
physical cell ID of the component carrier is set or changed
individually, it is possible to make power amplification in the
transmission section 108 efficient.
Embodiment 4
[0120] A base station apparatus of A-EUTRA according to Embodiment
4 of the invention will be described below with reference to
drawings. In this Embodiment, the phase rotation amount in the time
domain is controlled corresponding to the physical cell ID. By
controlling the phase rotation amount in the time domain
corresponding to the physical cell ID, signals of adjacent cells
(having different physical cell IDs) rotate in phase independently
with time, and it is possible to randomize interference. FIG. 4 is
a block diagram illustrating a schematic configuration of a base
station apparatus according to this Embodiment. The base station
apparatus 400 adopts a configuration obtained by adding a physical
cell ID/phase rotation offset amount correspondence table 401,
physical cell ID/phase rotation amount correspondence table 402 and
counter 403 to the configuration of the conventional base station
apparatus.
[0121] The base station apparatus performs coding of transmission
data for each component carrier in coding sections 101-1 to 101-n.
Further, the apparatus modulates the coded signals in modulation
sections 102-1 to 102-n. Furthermore, the apparatus generates
synchronization channels and reference signals in SCH/RS generating
sections 103-1 to 103-n, based on the physical cell ID (common to
all component carriers) and generation timing notified from the
control section, described later.
[0122] Multiplexing sections 104-1 to 104-n multiplex signals
modulated in the modulation sections 102-1 to 102-n, and the
synchronization channels and reference signals generated in the
SCH/RS generating sections 103-1 to 103-n on an OFDM-symbol basis.
Phase rotation sections 105-1 to 105-n rotate the signals
multiplexed in the multiplexing sections 104-1 to 104-n by a phase
designated by the control section, described later. The component
carrier multiplexing section 106 maps the signal corresponding to a
single OFDM symbol subjected to phase rotation in the phase
rotation sections 105-1 to 105-n for each component carrier to the
frequency region as shown in FIG. 9. The frequency/time transform
section 107 transforms the signal in the frequency domain
multiplexed in the component carrier multiplexing section 106 into
a signal in the time domain by IFFT computing. The transmission
section 108 converts the digital signal that is transformed into
the signal in the time domain into an analog signal, places the
signal on a carrier wave of a predetermined frequency to perform
power amplification, and transmits the signal. In addition, the
above-mentioned coding section 101-1 to transmission section 108
constitute the transmission processing section.
[0123] Meanwhile, the base station apparatus 400 converts a signal
received from a mobile station apparatus into a digital baseband
signal in the reception section 110. Further, the base station
apparatus demodulates signals in demodulation sections 111-1 to
111-n for each component carrier, and decodes the demodulated
signals in decoding sections 112-1 to 112-n. In addition, the
above-mentioned reception section 110 to decoding section 112-n
constitute the reception processing section.
[0124] The control section 113 controls each component of the
above-mentioned transmission processing section and reception
processing section. The upper layer 115 outputs a transmission
signal to the above-mentioned transmission processing section,
receives a reception signal from the reception processing section,
and outputs control information to the control section 113.
[0125] The physical cell ID/phase rotation offset amount
correspondence table 401 associates the physical cell ID with the
phase rotation offset amount in the time domain to store.
Meanwhile, the physical cell ID/phase rotation amount
correspondence table 402 associates the physical cell ID with each
phase rotation amount of the component carrier to store. Further,
the counter 403 performs count by control of the control section
113.
[0126] In the above-mentioned base station apparatus 400, component
carrier transmission signals generated up to multiplexing sections
104-1 to 104-n are provided with individual phase rotation for each
component carrier designated from the control section 113 in the
phase rotation sections 105-1 to 105-n, respectively. Each phase
rotation amount is designed by the control section 113 based on the
physical cell ID/phase rotation amount correspondence table 402,
physical cell ID/phase rotation offset amount correspondence table
401, and a value of the counter 403.
[0127] More specifically, assuming that d is a physical cell ID, Rc
(d,f) is a phase rotation amount of a component carrier f stored in
the physical cell ID/phase rotation amount correspondence table,
and that .DELTA.R (d, t) is a phase rotation offset amount in a
counter value t stored in the physical cell ID/phase rotation
offset amount correspondence table, the phase rotation amount R (d,
f, t) of each component carrier in the counter value t is given by
the following equation:
R ( d , f , t ) = Rc ( d , f ) + T = 0 t .DELTA. R ( d , T ) [ Eq .
2 ] ##EQU00001##
where the following equation is the condition:
T = 0 S - 1 .DELTA. R ( d , T ) = 0 [ Eq . 3 ] ##EQU00002##
[0128] S in the above-mentioned equation is a period, and when the
value of the counter is counted up from "0" to S-1, the value is
next "0". According to the above-mentioned condition, the phase
rotation amount R is given a different offset amount for each
physical cell ID whenever count-up, and returns again to the phase
rotation amount prior to addition of the offset after the period
S.
[0129] For example, in the case where count-up of the counter is
made for each sub-frame, and the period S is set at "10", the phase
rotation amount for each sub-frame varies at one-frame
(ten-sub-frame) intervals. Meanwhile, count-up of the counter is
made for each OFDM symbol, the period S is set at "14", and it is
thereby possible to vary the phase rotation amount at intervals of
one sub-frame. Further, when count-up is made for each frame, the
phase rotation amount for each frame varies at intervals of a
plurality of frames. In this case, it is possible to determine a
frame that is the reference to start count-up based on the system
frame information (SFN) included in the primary broadcast channel
(P-BCH).
[0130] The signal subjected to phase rotation for each component
carrier is placed on a subcarrier of an A-EUTRA frame in the
component carrier multiplexing section as in the conventional case,
transformed into a signal in the time domain in the frequency/time
transform section, and is transmitted from the transmission
section.
[0131] Described next is the operation of the mobile station
apparatus of EUTRA and the mobile station apparatus of A-EUTRA in a
system using the above-mentioned base station apparatus. The mobile
station apparatus of EUTRA is capable of receiving only a single
component carrier in a frame of A-EUTRA. Herein, in a single
component carrier in this Embodiment, all subcarriers are provided
with uniform phase rotation within a period of count-up of the
counter.
[0132] Therefore, in the mobile station apparatus that receives
only the component carrier, the mobile station apparatus that
performs propagation path compensation for each period of count-up
is capable of compensating for phase rotation provided in the base
station apparatus in performing propagation path compensation, and
the mobile station apparatus of EUTRA that connects with the base
station apparatus using each component carrier is capable of
performing communications without requiring additional processing
according to the invention. Further, also in the case of performing
propagation path compensation while exceeding the period of
count-up, by controlling the value of .DELTA.R to within
conceivable time variations in the propagation path, it is possible
to reduce the error in propagation path compensation.
[0133] The mobile station apparatus of A-EUTRA will be described
below. FIG. 5 is a diagram illustrating a schematic configuration
of a reception processing section of an A-EUTRA mobile station
apparatus according to this Embodiment. The reception processing
section 500 of the mobile station apparatus converts a reception
signal into a baseband signal in a reception section 501. A
synchronization processing section 502 detects a synchronization
channel from the signal received in the reception section 501, and
performs synchronization processing. A time/frequency transform
section 503 transforms the signal in the time domain into a signal
in the frequency domain at timing synchronized in the
synchronization processing section 502. A component carrier
dividing section 504 divides the signal in the frequency domain
transformed in the time/frequency transform section 503 into
signals of respective component carriers.
[0134] Phase rotation sections 505-1 to 505-n provide the signals
of respective component carriers divided in the component carrier
dividing section 504 with phase rotation designated from a control
section, described later. Propagation path compensation sections
506-1 to 506-n perform propagation path compensation based on
reference signals included in the signals undergoing phase rotation
in the phase rotation sections 505-1 to 505-n. Demodulation
sections 507-1 to 507-n demodulate the signals undergoing
propagation path compensation in the propagation path compensation
sections 506-1 to 506-n. Decoding sections 508-1 to 508-n decode
the demodulated signals. An upper layer 509 receives the decoded
signals.
[0135] The control section 510 controls each component. A physical
cell ID/phase rotation amount correspondence table 511 associates
the physical cell ID with each phase rotation amount of the
component carrier to store. A physical cell ID/phase rotation
offset amount correspondence table 512 associates the physical cell
ID with the phase rotation offset amount in the time domain to
store. A counter 513 performs count by control of the control
section 510.
[0136] Described next is the operation of the reception processing
section 500 of the mobile station apparatus configured as described
above. First, the reception section 501 converts a received signal
into a digital baseband signal to input to the synchronization
processing section 502. The synchronization processing section 502
detects the frequency including the synchronization channel to
acquire synchronization, and acquires physical cell ID information
from the synchronization channel. Further, from the primary
broadcast channel, the section 502 acquires information such as the
antenna information and system frame number required for
communications. The acquired information is sent to the upper layer
509, and the upper layer 509 notifies the control section 510 of
information required for subsequent signal demodulation.
[0137] The control section 510 controls each section based on the
control information from the upper layer 509. An output from the
reception section 501 is subjected to FFT transform on an OFDM
symbol basis in the time/frequency transform section 503 based on
the timing information from the control section 510, and is
transformed into a signal in the frequency domain. The transformed
signal in the frequency domain is divided into information for each
component carrier in the component carrier dividing section 504,
and is output to respective phase rotation sections 505-1 to
505-n.
[0138] The control section 510 counts up the counter 513 based on
synchronization timing and system frame information notified from
the upper layer 509, and provides each component carrier with
inverse phase rotation to phase rotation provided in the base
station apparatus, based on the physical cell ID/phase rotation
amount correspondence table 511, physical cell ID/phase rotation
offset amount correspondence table 512, and the value of the
counter 513.
[0139] The phase-rotated signals are input to the propagation path
compensation sections 506-1 to 506-n, and undergo propagation path
compensation based on the reference signal included in the
reception signal. The signals subjected to propagation path
compensation are demodulated in the demodulation sections 507-1 to
507-n, decoded in the decoding sections 508-1 to 508-n, and
notified to the upper layer 509.
[0140] According to the aforementioned processing, when the A-EUTRA
mobile station apparatus performs propagation path compensation
exceeding the period of count-up, the mobile station apparatus
removes a phase rotation offset added in the base station apparatus
before the propagation path compensation section, and is thereby
capable of performing propagation path compensation with high
accuracy.
[0141] According to Embodiment 4, in the case of using the same
physical cell ID among component carriers, by using the base
station apparatus of this Embodiment, the EUTRA mobile station
apparatus and A-EUTRA mobile station apparatus are capable of
performing propagation path compensation with increases in PAPR
(CM) suppressed while maintaining compatibility with EUTRA.
Further, by designating different phase rotation offset amounts for
each physical cell ID, phases of transmission signals between base
stations vary independently at count-up intervals, and it is
possible to randomize interference imposed on mobile station
apparatuses that receive signals in the cell boundary.
[0142] In addition, in this Embodiment, the tables are provided to
generate the phase rotation amount, but the invention is not
limited thereto, and the offset amount may be set using a sequence
that is uniquely calculated from the physical cell ID. Further, the
offset amount may be generated with ease by setting the period S at
an even number, generating code sequences comprised of S/2 "1"s and
S/2 "0"s corresponding to the number of physical cell IDs, and from
the beginning of the code sequence, sequentially setting the offset
at x degrees in "0", while setting the offset at -x degrees in "1",
or the like.
Embodiment 5
[0143] A base station apparatus of A-EUTRA according to Embodiment
5 of the invention will be described below. In Embodiment 3, when
physical cell IDs of part of component carriers are different, the
CM is calculated again, and the phase rotation amount is obtained.
In this Embodiment, it is beforehand defined to perform any
processing described below without calculating the CM.
[0144] (1) Using the physical cell ID/phase rotation amount
correspondence table of Embodiment 1 that holds optimal phase
rotation amounts for each component carrier in the case that all
component carriers are provided with the same physical cell ID,
applied is the phase rotation amount associated with the component
carrier number in the physical cell ID of each component carrier.
For example, in the case of using the physical cell ID/phase
rotation amount correspondence table in the following table, the
phase rotation amount of each component carrier is (Ro1, Ro2, Ro3,
Ro4, Ro5) when the physical cell ID of all component carriers is
"0", and when the physical cell ID of each component carrier is (0,
1, 2, 0, 0), the phase rotation amount is (Ro1, Ro7, Ro13, Ro4,
Ro5).
TABLE-US-00005 TABLE 5 Phase rotation amount for each Physical
component carrier number Cell ID n = 1 n = 2 n = 3 n = 4 n = 5 0
Ro1 Ro2 Ro3 Ro4 Ro5 1 Ro6 Ro7 Ro8 Ro9 Ro10 2 Ro11 Ro12 Ro13 Ro14
Ro15 . . . . . . . . . . . . . . . . . .
[0145] (2) When the physical cell ID of any of component carriers
is a different ID from the others, the phase rotation amounts of
all component carriers are set at "0".
[0146] By defining adopting any processing as described above, the
need is eliminated for notifying the mobile station apparatus of
the phase rotation amount, while keeping the CM value low.
Embodiment 6
[0147] A base station apparatus of A-EUTRA according to Embodiment
6 of the invention will be described below. In Embodiment 2
described previously, the phase rotation amount is set on a
90-degree basis, and the circuit scale is thereby simplified while
maintaining PAPR (CM) characteristics. This Embodiment describes
the technique for varying the basis for phase rotation amount
corresponding to the number of aggregated component carriers, and
thereby effectively obtaining PAPR characteristics while
suppressing increases in the circuit scale.
[0148] The following table is to derive optimal CM values from
among combinations of all phase rotation on each phase rotation
basis, in the case that the number of aggregated component carriers
is "3", "4" and "5", the physical cell ID is "31", and the basis
for phase rotation amount in each component carrier is 45 degrees,
90 degrees, and 180 degrees.
TABLE-US-00006 TABLE 6 The number of aggregated CM value associated
with the basis component for phase rotation amount carriers 45
degrees 90 degrees 180 degrees 3 6.22 7.37 7.37 4 6.80 6.98 6.98 5
6.36 6.51 6.55
[0149] From this table, it is understood that a difference of more
than 1 dB arises between a 45-degree basis and a 90-degree basis
when the number of component carriers is "3", and that any
significant difference does not arise due to the basis for phase
rotation when the number of component carriers is "4" and "5". From
the fact, when the basis for phase rotation amount is set at D3, D4
or D5 in the case where the number of aggregated component carriers
is "3", "4" or "5", respectively, the basis for phase rotation
amount is determined so as to meet the condition of
D3.ltoreq.D4.ltoreq.D5, and it is thereby possible to simplify the
circuit scale corresponding to the number of component carriers
aggregated in each base station apparatus.
[0150] Further, the mobile station apparatus that receives signals
transmitted from the above-mentioned base station apparatus varies
the rotation amount basis in the phase difference determining
section of the mobile station apparatus of FIG. 12 described in
Embodiment 1, corresponding to the number of component carriers of
the connected base station apparatus, and is thereby capable of
reducing the determination error.
[0151] The above-mentioned Embodiments 1 to 6 describe the base
station apparatuses that combine component carriers to transmit,
but the invention is not limited thereto, and in uplink of a mobile
station apparatus, the phase rotation sections described previously
are applicable to transmission processing of the mobile station
apparatus.
[0152] Further, in the descriptions of above-mentioned Embodiments
1 to 5, the phase rotation amount is calculated and determined
based on the physical cell ID, which is equivalent to determining
the phase rotation amount based on a signal waveform in
transmitting a reference signal, primary synchronization channel,
secondary synchronization channel, or broadcast information channel
that is determined based on the physical cell ID.
DESCRIPTION OF SYMBOLS
[0153] 100, 200, 300, 400 Base station apparatus [0154]
101-1.about.101-n Coding section [0155] 102-1.about.102-n
Modulation section [0156] 103-1.about.103-n SCH/RS generating
section [0157] 104-1.about.104-n Multiplexing section [0158]
105-1.about.105-n Phase rotation section [0159] 106 Component
carrier multiplexing section [0160] 107 Frequency/time transform
section [0161] 108 Transmission section [0162] 110 Reception
section [0163] 111-1.about.111-n Demodulation section [0164]
112-1.about.112-n Decoding section [0165] 113 Control section
[0166] 114 Physical cell ID/phase rotation amount correspondence
table [0167] 115 Upper layer [0168] 116 CM calculating section
[0169] 401 physical cell ID/phase rotation offset amount
correspondence table [0170] 402 Physical cell ID/phase rotation
amount correspondence table [0171] 403 counter [0172] 500 Reception
processing section [0173] 501 Reception section [0174] 502
Synchronization processing section [0175] 503 Time/frequency
transform section [0176] 504 Component carrier dividing section
[0177] 505-1.about.505-n Phase rotation section [0178]
506-1.about.506-n Propagation path compensation section [0179]
507-1.about.507-n Demodulation section [0180] 508-1.about.508-n
Decoding section [0181] 509 Upper layer [0182] 510 Control section
[0183] 511 Physical cell ID/phase rotation amount correspondence
table [0184] 512 Physical cell ID/phase rotation offset amount
correspondence table [0185] 513 Counter [0186] 1200 Reception
processing section [0187] 1201 Reception section [0188] 1202
Synchronization processing section [0189] 1203 Time/frequency
transform section [0190] 1204 Component carrier dividing section
[0191] 1205-1.about.1205-n Phase rotation section [0192]
1206-1.about.1206-n Propagation path compensation section [0193]
1207-1.about.1207-n Demodulation section [0194] 1208-1.about.1208-n
Decoding section [0195] 1209 Upper layer [0196] 1210 Control
section [0197] 1211 Phase difference calculating section [0198]
1212 Phase difference determining section
* * * * *
References